Revelation 2c

The name Smyrna may have been taken from the ancient Greek word for myrrh, smýrna, (Strabo, Stephanus of Byzantium) which was the chief export of the city in ancient times.
Myrrh is bitter to taste but sweet to smell. It has an association with sorrow and death and was used to embalm the dead (John 19:39).
The church here faced bitter persecution and death, but emitted a fragrant testimony of faithfulness to Christ.